Shed Skin is an experimental Python-to-C++ compiler. It can convert many Python programs into optimized C++ code, without any user intervention such as adding type declarations. Its main purpose is to optimize algorithmic-like Python code, by applying advanced global type inference techniques.

From page 1 of "Compilers: Principles, Techniques, and Tools":
"Simply stated, a compiler is a program that reads a program written in one language - the source language - and translates it into an equivalent program in another language - the target language."

So, python being the source language, and C++ the target language, this is a compiler by definition.